Die holder and tailstock center



Sept. 4,1945.- A. sARossY DIE HOLDER AND TAILsTooK CENTER y Filed ov. 9,1943 iwf' nnnnnn INI/ENTOR.

V/llllllllll Patented Sept. 4, 1945 UNITED .sr-Ares PATENT 'OFFICE2,383,991 Dm HOLDER AND TAlLs'roCK CENTER Albert lSarossy, West Orange,N.`J. l y ',applie'ationNovember 9, 1:94a, serial No.f5o9,5 61 v l (C1.iti-99) 8 Claims.

This invention relates to die holders vand .tailstock centers, and more'particularly to Van imv provement therein.

'The improved die holder-consists of 4two parts, a die housing and aguide-bar, which may :be `ma'de in sizes suitable `for bench lathes vandfor en'ginelathes. y

The `invention-consists in adie holder r1n wh1ch 'the threads Amay beout a't right angles, because the 'die rests flat -against the squarelysurfaced recess 'in "the die housing. The die `'cannot vbe moved 'duringthe threading operation because it is 'securely locked. vIt isabsolutely concentric with 'the stock to be cut and it remains so`because the die housing revolves freely around :a cylindrical part ofvthe guide or improved :and novel "tailstock center. The thread is cutwith 'a locked tailstock. The tailstock Vneed not be 'pushed-againstthe-stock while cuttingthe threads as "heretofore The die lhousing withIits .dies yields longitudinally to any-pull of the work, Athus 'thereis no dangerof stripping the thread caused by the weight'ofthe'tailstock. 'The smallest :force will Apull the die housing along theguide or vtailstock'center towards the -work piece-so that there is-nostrain on -the thread. .The lathe may be `revolved at top speed `because`the `die `is held *.se-

`cure, 'and there isno-possibility of itfgetting out 'of alignment yfromthe workipiece, and `therefore ithe I`threads maybe cut 'faster and moreeffectively than heretofore, reducing the :cost `of opferation.

-In the iprior vart .the entire `tailstock was subfjected toa `pullingand/or pushing action when the workpiece was being worked on. :In theim- 9 provement, the weight or pull is Yso little that 'the iinest'thread 'can be cut, and very delicate .workfcarried out, Abecause ofthegive instead of` the pull. All .parts are axially in alignment, andaztrue cutis obtained.

The invention will be more fully described hereinafter, an embodimentyshown inthe drawing, and the invention will be nallypointedout inltheclaims.

.In the. accompanying drawing, y

'Fig. -l is `aA longitudinal section of the improved die holder andtheguide bar for the same;

Fig.'2 is anend view thereof,` partly broken away; p

LliigJS'is an end'view from the other end;

Figxl is Aa'section online 4--4 of Fig, 1;

tFig. i5 -is *af perspective view -showing the inser- *tion "f lthe dieholder `vwith the guide '-.bar -in dttedllines;

Fig. 6 is a perspective vie. 'Lof'.the;guide-"liar;y

Fig. is a central longitudinal section of a tailstock with an improved-tailstock center, supporting the improved die holder and guide barapplied thereto shown in sideview and partly in section, and v 'i Fig. 8is a perspective View of the tailstock, guide bar, and work piece, toshow their operative relationship.

Similar characters of reference indicate cor-y responding pa-rtsthroughout the various views.,

l from rotating. In the manner well known, the

tailstock spindle t0 has a nut Mia or a direct thread engaging atailstock screw 4I which -isv se. cured to a hand wheel I2, the rotationof lwhich wheel and screw slides the tailstock spindle -40longitudinally. The work is indicated by I3, it beingsupported in achuck' Ita in a manner Well known, as shown in Fig. 8.

The cylindrical member ortailstock spindle 40 has a tapered bore 42.Into this bore there is inserteda novel tailstock center hereinbeforereferred to a guide bar having a tapered stem I6, having a shoulder Il,and a cylindrical holding and guiding portion I8. The tapered tailstockcenter and tapered seat in the tailstock spindle engage each otherfrictionally so that the new tailstock center does not rotate withrespect to the spindle.

The cylindrical portion I8 of the tailstock center fits into acylindrical bore I9 of a die supporting member 2D, `and has the shoulderI7 yabutting against the end wall 2l of the die supporting member 2D.This member 2,0 is rotatable and slida'ble on the portion I8. An oilermay be provided to permit oiling of the cylindrical part or shaft l8.`Oiling the cylindrical shaft I8 may be carried out by lany suitablemeans.

The member 2U has an enlargement 2li having a bore 25 snbcaliber to the[bore 19. These bores may be, if desired, of the same diameter asA thebore of the part 20 as in Fig. 8, or it maybe larger. The length of thebore '25 must be such as tojaccommodate the length Iof the entering endof the Work piece. The .bore .25 permits the yentry 0i the work piece I3during the operation of the dies. 'Ihe outer surface of the enlargementis knurled. At the end of the enlargement circumferentially arranged setscrews 2l preferalbly of the Allen type hold a threader 3l) or dies. Thethreader 30 is seated in a seat 30a, which seat [being at 90 to the axisof the threader assures that the axis of the threader is co-axial withthe member 2U, and work piece. As known, the threaders are replaceableto conform to different sizes.

When it is desired to substitute one threader for another, the screws2'I are withdrawn, one threader removed, and another threadersubstituted, and then the screws are again `fastened against thesubstituted threader.l f

Thus, the improved die holder consists of the novel die housing and thenovel tailstock center |66 The tapered end `Ilia of the tailstock centeror guide-bar dits into the tailstock` spindle proper. The die housing 2Bfits over the cylindrical end of the tailstock center or guide-bar I6.It is preferalbly made of cold rolled steel and both are preferably casehardened to insure long wear. It is preferably made in several sizes, tohold standard size dies. It will hold dies to cut threads from thesmallest to one-half inch diameter fine thread size or larger.

When .cutting thread the knurled part 24 of the member 2U is hel-d byhand pressure. After a few revolutions thethreading action will pull themember 20 forward on the guide-bar or tailstock center. The cylindricalstem I8 has scorings to indicate the length of the thread to be cut,preferably graduated 1A? apart. When the memiber 20 has moved slidablyon the stem I8 the desired amount of thread length to be cut, the handpressure on the knurled part 24 is released,

` then the lathe is stopped andreversed, the memberv 20 again held, andthe work piece unscrews itself, pushing the member 211 back on thecylindrical portion I8. l

It will have been noted .that the 'member 20 moves axially o-n theguide-bar or tailstock center the amount of the length of thevthreaclrto be made, Wherelby a fast, delicate: and true action results.

A very iine adjustment is made possible by the use of theimproved'device. First the work piece is supported in position. Then thepart I il is longitudinally moved towards the work piece and fastened inposition by nut Illa. Then the cylindrical part 40 is moved :by the handwheel I2, all of which secures a very accurate adjustment of the die tothe work piece. The fact that the member 2G axially and easily slides onthe guide bar I6, removes any possibility of a pull `or push on thetailstock. Contrary to the old practice the work piece does not pull orpush on the tailstock in its entirety, thus eliminating any possibilityof stripping or marring the threads being cut. i

In the improved holder, there is a delicate axial movement on the stem,and this sliding action trues the threads.

Theimproved die holder for lathes is especially adapted for smallthreads'lbut may be adapted to larger threads and to turret lathes, orthe like.

The improvement has special advantages for all shops,l especiallyfor theshopswho use it as an attachment for existing lathes without having toinstall separate vand special screw machines which might idle a largepart of the time.

Due to the construction described, the improved device can'be adjustedinabout iifteen seconds, which is considerably faster than the timerunning into minutes required by the earlier forms.

An embodiment of the invention has ibeen described, but obviouslyvarious changes may be made in the details disclosed without departingfrom the spirit of the invention as setout in the following claims.

What I claim is:

1. A die holder for tailstock spindles comprising a die supportingmember having a' bore for the entry of the workpiece, and having asleeve having a cylindrical bore and a guide bar cylindrical at one endin registration with the cylindrical bore, and tapering towards theother end adapted for entrance in the tailstock spindle to be heldthereby, said cylindrical end having graduated markings for indicatingthe desired movement of the die supporting member on its registeringcylindrical portion, the cylindrical bore of the said member andcylindrical end of the guide bar being slidable and rotatable in respectto each other.

2. A die holder for tailstock spindles comprising a die supportingmember having a bore for the entry of the work piece, and having asleeve having a cylindrical bore and a guide bar cylindrical at one endin registration with the cylindrical bore and tapering towards the otherend adapted for entrance in the tailstock spindle to be held thereby,said cylindrical end having graduated markings for indicating thedesired movement of the die supporting member on its registeringcylindrical portion, the cylindrical bore and cylindrical end beingslidable and rotatable in respect to each other, said cylindrical memberhaving a shouder limiting .its movement against the die supportingmember, and said die holding member having a recessed portion at its endfor holding a replaceable die, and having its exterior portion knurled.

3. In a die holder for tailstock spindles, the combination of a dieholding portion having a die for actingy on a work piece at one end andan extended supporting portion at the other end having a bore ofcircular cross section, and a guidebar engaging the supporting portionin rotatable and axially slidable connection therewith, havwork pieceVwithout exerting any pull or push upon said guidebar.

4, In a die holder for tailstock spindles, the combination of avdieholding portion having a die for acting on a work piece at one end and:an extended supporting portion at .the other end having a bore ofcircular cross section, and a guidebar engaging the supporting portionin rotatable and axially slidable connection therewith, having a partconforming to said bore of the ,guide holding portion, and having a partadapted to engage non-rotatably and non-slidably, the .spindle ofatailstock, and having means limiting the said slidable connection,permitting the die lholding portion with its die to move along with thework piece without exerting any pull or push upon said guide bar, ksaiddie holding portion having a seat at right angles to the axis ofsaid.portion for the die to seat axially with said p01'- tion and the workpiece.

5. A die holder for tailstock spindles comprising a die supportingmember having a bore for the entry of a work piece and having a sleevehaving a cylindrical bore, and a guide bar cylindrical at one end inregistration with the cylindrical bore of the die supporting member andin axially slidable and rotatable connection therewith, and taperingtowards the other end adapted for entrance in the tailstock spindle andto be held thereby.

6. In a die holder for' tailstock spindles, the combination of a dieholder having a recessed portion at one end for the reception of. a dieto act on a work piece and having a bore one end of which is incommunication with the bore of the die for the passage of the workpieceinto said bores, and having a bore at the other end of the die holder ofcircular cross section, and a guidebar for said die holder having oneend of substantially the same cross section as that of the circularbore, and having its other end of a coniiguration to register with thebore of the tailstock to be locked therein, whereby the die holder andsupport are in rotatable and axial relationship with each other duringthe action of the die upon the work piece, avoiding any pull or pushupon the support or upon the tailstock.

'7. In a die holder for tailstock spindles having a bore taperinginwardly, the combination of a guidebar having a part tapering outwardlyadapted to rictionally engage said bore against rotation and having apart forming a cylindrical` extension, with a shoulder disposed betweensaid parts, and a, die supporting member having a cylindrical bore ofsubstantially the same diameter as that of the cylindrical extension forrotatably and slidably engaging said cylindrical extension, and havingat its other end a die for acting upon a workpiece, and a bore for theentrance of the workpiece held by a chuck, whereby upon the workpiecebeing operated upon by the die, the die supporting member longitudinallymoves on said cylindrical extension, said shoulder limiting saidmovement, with the cylindrical extension remaining stationary, so thatany pull or push of the work piece is taken up by the diesupportingmember in axial longitudinal movement without exerting any pull or pushupon the cylindrical extension or upon the tailstock.

8. In a die holder for tailstock spindles having a bore taperinginwardly, the combination of a guidebar having a part tapering outwardlyto frictionally engage said bore against rotation, andhaving a partforming a cylindrical extension, with a shoulder disposed between saidparts, and a die supporting member having an exterior knurled portionand a, cylindrical bore of substantially the same diameter as that ofthe cylindrical extension for rotatably and slidably engaging saidcylindrical extension, and having. at its other end a bore for theentrance of a work piece and a recessed portion for a die for actingupon the work piece, whereby upon the work piece being operated upon bythe die, the die supporting member longitudinally moves on saidcylindrical extension, said shoulder limiting said movement, with thecylindrical extension remaining stationary, so that any pull or push ofthe Work piece is taken up bythe die supporting member in axiallongitudinal movement without exerting. any pull or push upon thecylindrical extension or upon the tailstock, the die supporting memberbeing held by hand onv the knurled portion against rotation during theoperation of the die upon the work piece, and released for rotation withthe workpiece upon the completion of the work.

, ALBERT SAROSSY.

